Refrigeration units are commonly used in commercial environments for storing perishable items at reduced temperatures for example providing a cool room. Typically, such units consist of metal panels sandwiching an insulating material defining the perimeter of the cool room area. The temperature within the cool room may be controlled by a refrigeration system comprising a heat pump to remove heat from the cool room, thereby lowering the temperature of the cool room.
The heat pump operates against the natural flow of heat by removing the heat from the area to keep the temperature at a set point. Thus, when the temperature is higher inside or outside of the cool room, heat flows into the cooler area to overcome the difference in heat temperature gradient. These heat losses and gains affect the efficiency of the system, requiring more work to be done by the refrigeration unit to control the temperature of the room to the desired set point.
The heat pump may include at least one evaporator, compressor, condenser, and engine connected to the cooling room to pump heat out of the room. Typically such units provide 30% efficiency of the refrigeration unit, with heat losses being the major source reducing efficiency.
Commonly heat loss or gain is reduced by providing insulation between the cool room and the outer area. This is usually achieved by using polystyrene or polyurethane foam between a metallic skin to form the panels of the cool room. As the metallic panels are good conductors of heat, these panels rely on the thermal insulation properties of insulating polystyrene foam to restrict the flow of heat into the cool room.
A problem with the construction of insulated cool rooms is that heat gain can occur at the joint between adjacent insulated panels of the cool room thereby reducing the efficiency of the refrigeration unit.
Attempts have been made to overcome this problem by using a sealant such as fluid silicon sealant to seal the panels along the edge of the joints. However, this process is cumbersome and expensive due to the cost of the sealant compound and the necessity to manually pump the fluid into the joints after installation of the cool room panels.
Additionally previous joints have resulted in condensation and the collection of water occurring at the joints between the panels, thereby causing the steel of the panels to corrode and pit.
We have found a way to reduce the heat gains into the cool room thereby increasing the efficiency of the refrigeration unit. We have produced a new panel edge joint which substantially ameliorates the above problems or at least provides the user with a useful commercial choice.